En ese caso, simplemente puedes intercambiar los `dataclasses` estándar con `pydantic.dataclasses`, que es un reemplazo directo:

{* ../../docs_src/dataclasses_/tutorial003_py310.py hl[1,4,7:10,13:16,22:24,27] *}

1. Todavía importamos `field` de los `dataclasses` estándar.

2. `pydantic.dataclasses` es un reemplazo directo para `dataclasses`.

3. El dataclass `Author` incluye una lista de dataclasses `Item`.

INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>About the command <code>fastapi dev main.py</code>...</summary>

The command `fastapi dev` reads your `main.py` file, detects the **FastAPI** app in it, and starts a server using <a href="https://www.uvicorn.dev" class="external-link" target="_blank">Uvicorn</a>.

By default, `fastapi dev` will start with auto-reload enabled for local development.

INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>About the command <code>fastapi dev main.py</code>...</summary>

The command `fastapi dev` reads your `main.py` file, detects the **FastAPI** app in it, and starts a server using <a href="https://www.uvicorn.dev" class="external-link" target="_blank">Uvicorn</a>.

By default, `fastapi dev` will start with auto-reload enabled for local development.

                """
            ),
        ] = None,
        redirect_slashes: Annotated[
            bool,
            Doc(
                """
                Whether to detect and redirect slashes in URLs when the client doesn't
                use the same format.
                """
            ),
        ] = True,
        default: Annotated[
            Optional[ASGIApp],

    * Up to now the application would run, and raise an exception only when receiving a request with form data, the new behavior, raising early, will prevent from deploying applications with broken dependencies.
    * It also detects if the correct package `python-multipart` is installed instead of the incorrect `multipart` (both importable as `multipart`).